1. Field of the Invention
The present invention relates to a personal tabletop-type air cleaner to remove smoke of a cigarette, that can be placed on a desk, table, or a like.
The present application claims priority of Japanese Patent Application No. 2002-230668 filed on Aug. 7, 2002, which is hereby incorporated by reference.
2. Description of the Related Art
Conventionally, in an air cleaner of this type, as shown in FIG. 10, a suction port 1 of smoke is placed at a front 1A of the air cleaner and a blow-off port 2 of cleaned air is placed at a rear 2A of the air cleaner. It has configurations of an air flow passage which, figuratively speaking, are reverse to those of a fan. However, the conventional air cleaner has a problem. That is, when such the conventional air cleaner is put at a place being near to a wall or fittings at the rear 2A of the air cleaner, since its blow-off port 2 placed at the rear 2A of the air cleaner is blocked, very poor usability is provided.
To solve such the problem as above, an air cleaner is disclosed, for example, in Japanese Patent No. 3092112 which has been obtained by the applicant of the present invention. In the air cleaner disclosed in this patent, as shown in FIG. 11, only at a front 3A of the air cleaner is placed an opening portion 3 and on an inside of the opening portion 3 are placed an intra-device suction port 3i to suck cigarette smoke and a plurality of intra-device blow-off ports 3o, 3o, . . . to blow off cleaned air. More particularly, the intra-device suction port 3i is placed directly on an inside of the opening portion 3 in a manner that a central axis of the intra-device suction port 3i approximately conforms to that of the opening portion 3. On the other hand, the intra-device blow-off ports 3o, 3o, . . . are placed discretely at four places in a manner that a normal to a blow-off surface of each of the intra-device blow-off ports 3o, 3o, . . . is approximately orthogonal to a normal to an opening surface of the opening portion 3 at its four corners being positioned directly on an inside of a fringe of the opening portion 3. By configuring as above, since a vortex flow of cleaned air is blown from the intra-device blow-off ports 3o, 3o, . . . around cigarette smoke that is being sucked into the intra-device suction port 3i, dispersion of the cigarette smoke is suppressed and, as a result, improvement in smoke sucking efficiency is expected.
However, has turned out that complete formation of a vortex flow is, in actual fact, not easy and its cost is high. In other words, it is not easy to obtain such a stable vortex flow as desired by employing an air cleaner having a simple configuration, there is potentially a fear that an air flow that would impair suction of cigarette smoke occurs. A descending flow being produced by crumbling of the vortex flow and impinging on a desk, in particular, presents a problem since it causes documents on tables to wiggle and it is offensive to users.